multithreading

问题 This question would probably also apply to the general world of Java threads... I have a thread that I use like so (this is in the run method): Looper.prepare(); Handler rHandler = new Handler(){ @Override public void handleMessage(Message msg) { //ommited... } }; Looper.loop(); My question is whether the thread is using CPU while it's waiting for things to be pushed to the Handler? Or is it really "sleeping"? Can having a couple of such threads bog down the system? 回答1: Underneath the hood,

问题 I read about lock, though not understood nothing at all. My question is why do we use a un-used object and lock that and how this makes something thread-safe or how this helps in multi-threading ? Isn't there other way to make thread-safe code. public class test { private object Lock { get; set; } ... lock (this.Lock) { ... } ... } Sorry is my question is very stupid, but i don't understand, although i've used it many times. 回答1: Accessing a piece of data from one thread while other thread is

问题 This question already has answers here : How do I pass disjoint slices from a vector to different threads? (1 answer) How can I pass a reference to a stack variable to a thread? (1 answer) How to get mutable references to two array elements at the same time? (6 answers) Closed 2 years ago . I have a vector of u8 and I need to fill this vector with values that can be computed in parallel: let vector: Vec<u8> = vec![0, len]; Given n_threads threads, each thread can take care of a section of the

问题 This question already has answers here : How do I pass disjoint slices from a vector to different threads? (1 answer) How can I pass a reference to a stack variable to a thread? (1 answer) How to get mutable references to two array elements at the same time? (6 answers) Closed 2 years ago . I have a vector of u8 and I need to fill this vector with values that can be computed in parallel: let vector: Vec<u8> = vec![0, len]; Given n_threads threads, each thread can take care of a section of the

问题 While playing around with concurrent calls to println in Clojure I found that its behaviour is different from Java's System.out.println . What in Java I would write class Pcalls { public static void main(String[] args) { Runnable[] fns = new Runnable[3]; for (int i = 0; i < 3; i++) { fns[i] = new Runnable() { @Override public void run() { for (int i = 1; i <= 5; i++) { System.out.println("Hello iteration " + i); } } }; } for (Runnable fn : fns) new Thread(fn).start(); } } I paraphrased in

问题 I have multiple runnable classes and I want to run them with executor service through a centralized class (call it Launcher class which contains list of all runnables). I wrote a Launcher class which takes all the beans to instantiate using applicationContext.getBean() . Each runnable class also defines a pool size for it (number of threads to spawn for this runnable). public class DaemonsLauncher { @Autowired private ApplicationContext appContext; private List<Daemon> daemons = new ArrayList

问题 I have multiple runnable classes and I want to run them with executor service through a centralized class (call it Launcher class which contains list of all runnables). I wrote a Launcher class which takes all the beans to instantiate using applicationContext.getBean() . Each runnable class also defines a pool size for it (number of threads to spawn for this runnable). public class DaemonsLauncher { @Autowired private ApplicationContext appContext; private List<Daemon> daemons = new ArrayList

问题 I have multiple runnable classes and I want to run them with executor service through a centralized class (call it Launcher class which contains list of all runnables). I wrote a Launcher class which takes all the beans to instantiate using applicationContext.getBean() . Each runnable class also defines a pool size for it (number of threads to spawn for this runnable). public class DaemonsLauncher { @Autowired private ApplicationContext appContext; private List<Daemon> daemons = new ArrayList

问题 Lets say we have a class like so: public class Foo { private Bar bar = new Bar(); public void DoStuffInThread1() { var old = Interlocked.Exchange(ref bar,new Bar()); //do things with old //everything is fine here, I'm sure I have the previous bar value } public void OtherStuffFromThread2() { //how do I ensure that I have the latest bar ref here //considering mem cahces etc bar.Something(); } } And lets say we have two threads, one operating on DoStuffInThread1 and another on

问题 Lets say we have a class like so: public class Foo { private Bar bar = new Bar(); public void DoStuffInThread1() { var old = Interlocked.Exchange(ref bar,new Bar()); //do things with old //everything is fine here, I'm sure I have the previous bar value } public void OtherStuffFromThread2() { //how do I ensure that I have the latest bar ref here //considering mem cahces etc bar.Something(); } } And lets say we have two threads, one operating on DoStuffInThread1 and another on